SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd850c2bab7d6a4b4338d08516314fda6b4c8e2adfe3fce3c7abbc77dcb60bb5' 
  AND token = 'jXESFE3+K5KzqTQaWPwuqObGfd/tyZZuBzPGazwm14M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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