SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75c9bb46518303edcceaf843e02654a937493618f15dd09e3f30c07f4d5b2bd6' 
  AND token = 'C4H2SrtDMJKofbjntRzZywQEs5NXVizgF2WqTEvwEa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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