SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '933985b0dc6133307d8c79920ac44614008e7d4150956c2decb5f715363e3ecd' 
  AND token = '+OvUsqpFh8YSBPLfGNFtgLJSy76go+b/crGXRURNF1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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