SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '777567ed66bb2a5aa085c07616ca9d1fc5ce83d8138bbc106e44109585fab66a' 
  AND token = 'GFEY7JTPjvbLjkYqXHNQLMMJUse+dNtMr346HehTdt0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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