SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a672b25d8a470bef1ca455179a2c7a76c8b0b4a7381f400d21b6197907bca8f' 
  AND token = 'N/DRxToaAXcaOfISEjYF/gNV9nJV/M/X3OGMSpMJSN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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