SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08beaf9353ad5b8cc67b11ff805e44329b4b0b6210a111639ac8d60d0169c2ec' 
  AND token = 'WSg0M3bcPzeTjYDKQQ+UDUisPvOmTCFcAQIEnON5SBk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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