SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e950b34473056831fe823ed64ca77c59dfec18d7d9283334445f80d21cbca62d' 
  AND token = 'B1AwwjTKT9YIn9+phFcAg4zl1BuvuSQMiBSqt9O2MA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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