SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13c2613a4a908958125fbab750e5cab21b03265910f8697553863771be2774e6' 
  AND token = '8dVMmKtqdh+x3LwaW79GvnWZT7QKsbi7u55SyZHfuX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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