SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57fa72f60cf9df297cc8b7c6231d68d2d95027ec2df0394dd290ff6654c05f8d' 
  AND token = 'SQccgShm2WKErY1rY+tZ3gYBrTUtDrvnX/apkHv4P54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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