SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23f54f8adcb31b6ab248fcba245c690b8632067a1747ac7998f1d4cdcb7e4ea1' 
  AND token = 'QM3Dm09nMrgFqY+MAkoHvHEo8B4gHwFjXvZgDGG3oio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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