SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38df6aac73fb7415487b18b78ee30d46d57cbf0bf1cf2a797658dd975e850289' 
  AND token = 'nly0aRD/5BpfVcqhRvGAQYDXxuGSLL5NZJk6YN0t+l8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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