SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4ad41d1f35fe71bafea06c610224960731fa88c195cbe2f23750657c22650bb' 
  AND token = 'LDJD0WF1vaL+pZydFX+vGSskO4Eu9O4jNBeCIBm/7pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}