SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1a09199b5641b9dfa481f8a783de7a50a4146701be99bcaa50e8869b52c28f2' 
  AND token = '6WYZHpXka6Uz/E186JLsUd5KN05TIl7U3arvnV83nQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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