SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23cce32e21273233724a11a8a8beb48cb81ba049144e4961a5218d72ddad2bd3' 
  AND token = 'qLRwmeLm6JRnFOYcV4yUGj07IHauXdFVvFdxWdnOHCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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