SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '203955314aea7ab0b287aae5ca7e052d2d65acb26b517e69f18945df77430b4b' 
  AND token = 'C1FEQPS0DrKMIy+UkRGMYAHFILoaafig0IAqSNhCaSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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