SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed30af7c5f653245a6fa131807283254ba34d1ae2699af7317c2e3421903a7f6' 
  AND token = '3OqROre3N4dftLZjr7++Nn6NhOtEgMzId9jedn2eTNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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