SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0374bb251a743df74fef1db2513849b3e4031819b025bd891a8bc4473aa1dc74' 
  AND token = 'f+/uaZm8vkmqP/H/k/BJVjXPxdE5RFsXFkSoK6UiiUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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