SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbf63218fdec6b0c699c79373c5a38d71410b2ed14406043915bceced8eff9c3' 
  AND token = 'QIXPhDiWn3KRQCn6zk2R1P3ea2lTaI1+pIfxqVQpCvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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