SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3de24257fbf398f38ee3a933b20a99a2919e5fa6a69aa0c4ffd450a65ec3fe04' 
  AND token = '8NvfnPJPD/ItyXkp1PNK/M81paC9rv6REqI0zX4pUAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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