SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bfd0ce02356a54d5bebb85f7675dc6ccf4bd82a6ca6d451f0f9a6e49c56ac0b' 
  AND token = 'KmAy+ojaIJdLRCk87KfkNAwUJe2p2R6maaUiHcStSSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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