SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0872195d136b3ff879c318d03b201b0d31791cd553b6f0eaf186427e6966a366' 
  AND token = '0ml5C05y8MMBQhCFdS6i1UiY/o6Ko0COlUuUBtHaSq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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