SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5238d4aeb9182782619596d55bb89468412296d319d5355075c657eafd86345' 
  AND token = '6XP+mYzvgjjCC8MpxGs4r+9p5kFaZ88KzJ4b3E4cYFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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