SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84220f78da6f9330fd51948316c7d14df409d8f8e514dd9541ee88d767b3c634' 
  AND token = 'GmlCtGT6TOVC4DB1Olbg2lWqYkFGpgkJOndUgZjj44Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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