SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb54403da23f1b9d5dbcdd9fbe46bb4bd8dc53062d15d8b4f73f4a616324b7f1' 
  AND token = '0PcvjM9vzWjWUGwUP/i1MKX98WAs+zzaES3BnB/pxF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}