SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '011211d9b9eb251bed7d960525d1115fd186cada8bc937d81df41f212eea85fd' 
  AND token = '1WDdYNrq4lYhITzYJCqEO+smfgV7kXcAi3ah7YhKynE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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