SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bbb199f35fa5be28fcbd10c3f3956fb3102a520efc75ff96e659158bc858fd0' 
  AND token = 'xcX5LIXqkGYpKH3rvgmZrcVIwP1Ll+It/1uJNfnPh+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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