SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea8ca7dce495312b2c07498b3732fa805bfa16fbb644782762c58857a0f6805' 
  AND token = '96iryMgZu0P6sc3101034kUhUjisUM7kezZcZJLXZE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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