SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7d544ab286fca723b1fbd00cdfb5cc546a22326c9ced3f8b3bd515f978390fe' 
  AND token = '2BheehITwkfdx8f1Fv5/f/3iRjRjd/bzqjrEkFfHqS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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