SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dade3cc4d3b32e37b2d70706282d1b40bc739814eec799bb6b7897e4ef14a7b7' 
  AND token = 'cE++BVNMvdInVrO25nPPIevhBb68/nLAcbAHDGOrCWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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