SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe87db62157dafe6396fd8452cef233888688815c08accd2e32ad5fe5501e905' 
  AND token = 'Hv+R5zOzpzWMnCuCHdlEb92jzbMfviiwnoYbStFBpT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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