SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cfb859912efde58429ef314b7949661c5beddf85c94e07962769c43d568f0bae' 
  AND token = 'ldlahj1xTKyu9Zfk/2ACHgORQfw6zBrDDpOzS+APafQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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