SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '079ebba7c394b83e25cb37cf75314ab347ab9b821ebe4ed00ada45ffc8968b6c' 
  AND token = 'UBVsaflJTqs+OyKc1MzccrTrHUldQiMCCVqIUycY9aQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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