SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5dfffd97874cb9e5d5310541897fbd2706943ef5d8fd47d949a22bda94880cc' 
  AND token = '0qwhqSk4Nj5nbwdecBBG+d/JtJdbtUMQFjxv5TvBx8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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