SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7745486f0db017133a81ca7825e4ea3dec42bb299df764390d1fbe5678d4724' 
  AND token = '1lzDdIyPLYKowmOhfRTfKOMQ099Vau6hU/aliCy5vVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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