SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfc81b369dd23b0a93d96fed5241e16252dad529d48895c1bc73ea2d9966128a' 
  AND token = 'pHktKt7yvqab6ByAP0tlb4Kf6J0LP+IUpLedvVepWrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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