SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f25c82e803a165a20483ea861170e08b339ef99e66a8af595e0213b59e93c663' 
  AND token = 'BAiPdTrF8EBt4IOFQUft+PpiPmNOF/rI+Gb0xZCBLmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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