SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1751fcbd7084ef17852fce0b2a61c863cb024c8aa78537a184cd1e12ced8777f' 
  AND token = 'jKr+SOSwkzvrcQHMNJ2WS+4REauIGJLvtOa27XkZOfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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