SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa1a8e2b4f5dfb60f36fa1f86718d7e27aa31105f499fa6f4f817fd82fe0b7a5' 
  AND token = 'ldpwuT1p7dTkRvIFg8YwjnDNe3gF5hzvK9SRzToSYt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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