SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef6b391446c2e2795a9575ba010499633c27215af9c6ed4d523e465cda16155e' 
  AND token = 'fMze/22SOmWUAAZvNMedlIPf5+jrqWdCPOB8XuxVgNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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