SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '524eb876c7dcd8b844aed898a3680f2ee8f5ba28eaef66103186728ccc979f57' 
  AND token = 'BOwwPnnlgTEaA8eMHwGZx6qrdVPirysvotqYtd9qgRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}