SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '584ebd50d8502a99399f2f07399d464420ae051dc541089de5b746932a4e5bf1' 
  AND token = 'gg5DfGz5HXYiqIWonNpv+000UlEwuC2m2pdyqGFeMgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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