SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b865f8fcc9efd4c322b88ce876e89191f963dbcebfbdefa0b6deaede4bccfcd' 
  AND token = 'vqUPUOwQ3QrRbordfbLsHa00Xby6wtOl9RJYToH/aOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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