SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0059ad41bfa59d337fbb2160c0b558687a9c49333d5cd1f9b487d33792628a7' 
  AND token = '6T+OO9NgPlEFIX13mKyrBh10z+cMjXuQCBLJ7ADm4TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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