SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf47be5f651d0d306aac41255be9a88aeb764b4f69601eb61846b46bb7618849' 
  AND token = 'ZNlFLAJeh1pNGlaXCgK/yuiH/LspaG+CY+06NkVz7/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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