SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a0b563f974edaeefd8a2247e0d5e2e0d3d79f9360a108aa7039034da62b39e3' 
  AND token = 'fmj3z33NkMxKndx7ke/o6dEwcGrphdLyyfNmNzjS7NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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