SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd4725bbee3a326ee9bbfa8213d03b374dfa3037158ce96572ce26f33ce9b30c6' 
  AND token = 'T4rLEl4AgNSh4dQ/IOT4tReAbd6mRZnK4L5+/5OYR08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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