SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '629afbe9124bdd1911f12a58799293dcfa4c08ebfd55f5e33470284df921f46a' 
  AND token = 'nu81/MvgSAoA5hiVqMdMWmBRUpps0wQWZPb7199m6dU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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