SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bcb14de3d595ec37acd7fa5fd28bff83e427d229f38fb8b24ab307eb26d3af9' 
  AND token = 'KGHfd0qtNw4V2RmFGPgOICzoXfG81P/m+td9zGaZVNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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