SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '89af273c601e80824cda25fdc9e72ab6129c476cae75c408ffdef18300381e66' 
  AND token = '1ZIjSjQwK1J7idsS1LGz7s8lyhMRBySGyLhp1ucsuqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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