SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de45fdbabc674975255037863963961fa570bd279dab0ab8f34d5187bf1412f6' 
  AND token = '//AGU6uXSXDBKa7hjo31QLRssGAXbm2RjMsVXMX26yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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