SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4baecef32d940a78c5fdf055355ce909e2be6cacb9b34423e89bc31591e950b' 
  AND token = 'gQOOE8INVTtkOGN0Dmwf0JX1MV7LCZQy45O2HZHiSuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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