SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a30c4882661c28e664f1d8d5a1eafd38239b877aa290517ac5ac32468b1a266b' 
  AND token = 'BVOqzinseEfWD8FOM6rkkbKU6nSIEtl8lIeNFjM3Y+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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