SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e84534fb9343942d7d5aeec90ac6b7d39ccc19080d8c074bd6edc9c208f93e' 
  AND token = 'MB2EjW65Vh/pD+zYzElhYffYMl3x5AWgEFqmqhfQZAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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