SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69e3f02783a5d9ec535e207513a7cbe28746ec2f914f9e706697575dc87c3eb2' 
  AND token = 'r92g/JZasi7ndIZaYy0XROAvQY0GGkoijwQLEMJwNU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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