SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaee7dc1c7d4ad44b9f5d227993864fd60a49c915d9bff36414d68572727cf1a' 
  AND token = 'DK37FoqPqJ7t7AgirJbJln3Gh7jBBOwQcX/+17PN8/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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