SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47585ebbe9517f5213599423f19e7d8cbdffc02d8d39dc7d1881e7c76b5ff09d' 
  AND token = 'wftmY4pVRa7ocplvWrGyo4jEJSYgRqPLljoEeezCid8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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