SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c895ae84f07293737adf8e4fe7161df256792e3a2fc820471dfff5b47fcd355c' 
  AND token = 'FI80jgtrCoqKzZqvDT8VOxUMW/eBb9qseu2VMUQsyHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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