SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab843fb91707ae31f1abe6db6400004565d92bd236f56ef363f240d9648db614' 
  AND token = 'p7GIOeVaR99ywoWkKfnZhF9kfr/RMKjXiNebBIOvFwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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