SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '380a26b375480efd738ed2dff1564be79b3fbb083dcf24e31db4ab0434aa2216' 
  AND token = '5iJ13QojG2kb9B+NgqkYRpCiqkagXAXwlb3/irKG7IE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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