SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0ada2c82f603077f1869343acbddd910cfff9557f6fca00389599a938db5b33' 
  AND token = 'XE1Mq5tudc8fzKDDo3aExHaXakMNpd0YNnHcEuBzQv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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