SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ced3674afa3d989bf45c03b152ff5f43cae8f8e5c275e18f3b625bc9b29291bd' 
  AND token = 'ugqoxCqHvvXJWEjYDIE8m21tZ+TzqC5zHSnxvPzCAxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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