SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '665d0f5a24e66c91583a7b284483297b7808a6923e9daa1a54734cc6fc334a69' 
  AND token = '+BA69DJFp611BKAhLUYvI3gRM+8CfKCBUV0L9kG6p0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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