SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43b4d506558b4ae63ceda370488937b5ef06bea51ddbe5517c295eaba20e18d7' 
  AND token = 'FXHGD+G/VjbHwwPF3H36Y2cdbK++cyqz4rs105wGbQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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