SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b8b044db955aa0648855db3601f5fa13691635e4aac5348d681620a8d6bc5fb' 
  AND token = 'VI6j7cdpHS2Pnhk76rDazqpMtJNDT3C47rZI8OpVEqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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