SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4c55e6f7d94df6b8c905a2ed6413f7049fb1c1e882bbe039f5aac30a80800f1' 
  AND token = 'xGkk1k5+R53VE5dhA9/K/kc7k9UsRqViQdHwtxmr9vM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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