SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a0ce14f13a4b3ff657e5fecb0f74117155b72c64941c52ccf8d38ba23eadb1b' 
  AND token = 'YBW9w4LPQKrd9+nFHCI8AM/IuUawC6wnuVLcjXO2Oo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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