SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1280dcd398c3aedbacae46149134f451f8e81b2178e3ddc2e46e9cc91b1f8005' 
  AND token = 'PONHARP/DVoyda6UXRHtReUXRSe2bvuZdpBuXYDUfKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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