SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5c7b1d99bde1e848792aa9621a53f667482995436dde3ab426390e65e1d7841' 
  AND token = 'RAwvsMwMCraVpdkBRyEaZUj5y1WyNwUgGUfINFcN1A8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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