SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd075556dfd515a5e97739d68a1fccae035fa945f860a6c862c5be9953b37e260' 
  AND token = 'T4dxZiGxA1hcpjwQRin+Nvm2A3N7n+8MOp7TXt7wGow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}